This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Fluorescence tomography (FT) is a highly sensitive noninvasive method for preclinical imaging. With the success in our recent methodological development, we are translating the newly developed technology to preclinical in vivo imaging of mice with lung cancers. We have previously successfully conducted studies using the same animal model with microCT, in which vascularized tumors were significantly enhanced due to leakiness of the vasculature in the tumors. In the proposed study, we plan to test the hypothesis that fluorescent contrast agent can be used to enhance tumors via the same mechanism. In addition, due to the differences in biodistribution, we are also going to compare the differences in tumor enhancement using fluorescent and x-ray contrast agent.